Exercise: Conditionals

Create a program to calculate the BMI (body mass index) of a person. Ask the user for his height in meters and his weight in kg. 

Formula:

• BMI = weight / (height * height)
• Weight in Kg
• Height in Meters 

In case you want to use feet and inches for the height and pounds for the weight, you can use the following formula:

BMI = (weight / (height * height)) * 703

• Weight in Pounds
• Height in inches
• 1 foot = 12 inches

Print the BMI and the classification according to the following table.

Goodluck. Do the exercise and when you're done come back here to see the solution.

SOLUTION:

Let's start by asking for the height and weight of the person. I am going to use meters  and kilograms.

print("This program calculates your body mass index")

weight = float ( input("Type your weight in Kg (ex. 70.5): ") )
height = float ( input("Type your weight in Meters (ex. 1.70): ") )

bmi = weight / (height ** 2)

print("Your BMI is: ",round(bmi,2))

if (bmi <=18.5):
    classification= "Underweight"
elif(bmi > 18.5 and bmi <= 24.9):
     classification= "Normal weight"
elif(bmi > 24.9 and bmi <= 29.9):
     classification= "Overweight"
else:
    classification = "Obesity"

print("The classification of your BMI  is:", classification)
    

This is how our code will look like.

Using 70 kilos as weight and height 1.70 meters, let's run it to see if it's working:

== RESTART: C:/Users/ameny/OneDrive/Desktop/Python Revision/bmi_exercise.py ==
This program calculates your body mass index
Type your weight in Kg (ex. 70.5): 70
Type your weight in Meters (ex. 1.70): 1.70
Your BMI is:  24.22
The classification of your BMI  is: Normal weight
>>> 

And it's working. Our bmi is 24.2 and the classification is normal weight. You can try out different values to see the bmi classification. I hope you enjoyed doing this exercise? If you have any question just leave it in the comment section. 

I will see you in our next tutorial.